Abstract 4842
Background
The incidence of pancreatic cancer (PAC) has continued to rise in recent years. PAC can be divided into head of PAC (HPAC) and body/tail of PAC (BTPAC) by the anatomical location. The patients (pts) with BTPAC are usually diagnosed at relatively advanced stage and had worse survival than those with HPAC. The comparative molecular signatures between different locations in Chinese PAC pts remain unclear.
Methods
154 tumor specimens (HPAC, N = 85; BTPAC, N = 69) and matched normal blood samples of Chinese PAC pts were detected and analyzed in a CAP&CLIA certified laboratory (OrigiMed company) with Yuansu panel including 450 genes. Total 100 males (65%) and 54 females (35%) with a mean age of 61 years old (yrs) were enrolled. We measured the somatic variations and calculated tumor mutational burden (TMB) after filtering known driver mutations (muts). Meanwhile, germline muts were analyzed among the tumor susceptibility genes. Fisher tests were used for comparative analyses.
Results
The median age in HPAC and BTPAC was 60 yrs and 62 yrs. Pts with stage 3&4 accounted for 40% and 60% in HPAC and BTPAC (P<0.05). Genomic alterations of KRAS and SMAD4 were significantly more prevalent in BTPAC (KRAS in BTPAC vs. HPAC= 97% vs. 82%, P=0.004; SMAD4 in BTPAC vs. HPAC= 42% vs. 21%, P=0.008). 2 NTRK3 fusions (3%) were found in BTPAC but 0 in HPAC. Additionally, muts frequency in Wnt pathway was 57% in BTPAC, whereas 37% in HPAC (P=0.02). No significant difference was found in TP53 (83% vs. 81%), CDKN2A (32% vs. 27%) and germline muts frequency (12% vs. 14%) between BTPAC and HPAC, nor in the mean TMB value (3.22 muts/Mb vs. 3.59 muts/Mb). For HPAC, there were more muts in HR pathway genes (24% vs. 19%), although the difference was not statistical significance. 2 BRCA2 germline muts were found in HPAC but neither BRCA1 nor BRCA2 was found in BTPAC.
Conclusions
Genomic pattern did not show apparent difference between the anatomic locations of PAC. However, we found more driver muts in KRAS and SMAD4 and more Wnt pathway muts related to proliferation and metastasis in BTPAC. Further research should be done to better understand the cancer biology among the locations and identify more therapy targets for precision medicine.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2551 - Efficacy of dose-dense (DD) adjuvant chemotherapy (CT) in hormone receptor positive/HER2-negative early breast cancer (BC) patients (pts) according to immunohistochemically (IHC) defined luminal subtypes: an exploratory analysis of the GIM2 trial.
Presenter: Benedetta Conte
Session: Poster Display session 2
Resources:
Abstract
3426 - High dose Neo-adjuvant chemotherapy in Triple-Negative breast cancer with evidence of homologous recombination deficiency (HRD).
Presenter: Sonja Vliek
Session: Poster Display session 2
Resources:
Abstract
3792 - Risk factors for locoregional recurrence (LRR) after neoadjuvant chemotherapy: pooled analysis of prospective neoadjuvant breast cancer (BC) trials
Presenter: Gustavo Werutsky
Session: Poster Display session 2
Resources:
Abstract
4044 - Estimating radiotherapy-induced cardiovascular mortality in female breast cancer patients.
Presenter: Mark De Ridder
Session: Poster Display session 2
Resources:
Abstract
719 - 3-year follow-up of a phase III trial comparing the efficacy and safety of neoadjuvant and adjuvant trastuzumab and its biosimilar CT-P6 in HER2 positive early breast cancer (EBC)
Presenter: Justin Stebbing
Session: Poster Display session 2
Resources:
Abstract
3595 - Adjuvant chemotherapy in elderly breast cancer patients: pattern of use and impact on overall survival
Presenter: Axel Berthelot
Session: Poster Display session 2
Resources:
Abstract
3992 - Carboplatin-containing neoadjuvant chemotherapy for triple negative breast cancer (TNBC): a propensity score-matched study.
Presenter: Maria Vittoria Dieci
Session: Poster Display session 2
Resources:
Abstract
3477 - Impact of adjuvant trastuzumab emtansine (T-DM1) on incidence of metastatic breast cancer (mBC): an epidemiological model of patients with HER2-positive breast cancer (BC) who did not achieve pathological complete response (pCR) after neoadjuvant treatment (non-pCR)
Presenter: Mellissa Williamson
Session: Poster Display session 2
Resources:
Abstract
3928 - Chemotherapy (CT)-induced anaemia in patients (pts) treated with dose-dense regimen: Results of the prospectively randomised anaemia substudy from the neoadjuvant GeparOcto study
Presenter: Hans Tesch
Session: Poster Display session 2
Resources:
Abstract
2184 - The clinical impact of adjuvant dose-dense sequential chemotherapy (dds-CT) in patients with high-risk operable breast cancer (BC); pooled analysis of 6 clinical trials.
Presenter: Elena Fountzilas
Session: Poster Display session 2
Resources:
Abstract